16.20 - About Export Width Rules - Teradata Vantage NewSQL Engine

Teradata Vantage™ NewSQL Engine International Character Set Support

prodname
Teradata Database
Teradata Vantage NewSQL Engine
vrm_release
16.20
created_date
March 2019
category
Configuration
User Guide
featnum
B035-1125-162K

The character conversion parameters for all export width definitions, including any custom definitions you create, are stored as a rule set in the DBC.ExportWidth table, for example:

SELECT * FROM DBC.ExportWidth;

ExportDefinitionName    ExportWidthRuleSet
--------------------  	 -----------------------------------------
EXPECTED                1112211111222232222211121111112222322222
MAXIMUM                 1322323221332232322321123111122322323222
COMPATIBILITY           1112211111111231111111121111112222322222
CustomDefinition1       4112211111222232222211121111112222322224

Interpreting the Export Width Rule Set for EXPECTED

To determine the export width for a character set combination:

  1. Identify the ExportWidthRuleSet values that correspond to the server character set; for example, for the DBS Control export definition setting EXPECTED.

    Server Character Set Applicable Export Width Rule Set
    LATIN First set of 10 digits (1112211111)
    UNICODE Second set of 10 digits (2222322222)
    KANJISJIS Third set of 10 digits (1112111111)
    GRAPHIC Fourth set of 10 digits (2222322222)
    The ExportWidthRuleSet for a server character set is always in the same position for any ExportDefinitionName. For example, LATIN is always the first set of 10 digits.
  2. Within each set of 10 digits for a server character set, you can find the export width conversion multiplier for a session character set.
    The position in each group of 10 digits... Is the Conversion Multiplier for...
    First
    • Any session character set that ends in the string '_0I'
    • The session character set 'KATAKANAEBCDIC'
    Second Any session character set that ends in the string '_0U'
    Third Any session character set that ends in the string '_0S'
    Fourth The session character set 'UTF16'
    Fifth The session character set 'UTF8'
    Sixth Any site-defined session character set with STATEMACHINE EUC1211
    Seventh Any site-defined session character set with STATEMACHINE EUC1223
    Eighth Any site-defined session character set with STATEMACHINE S80
    Ninth Any site-defined session character set with STATEMACHINE S80A1E0
    Tenth Any site-defined session character set with STATEMACHINE SOSI0E0F
    For example:
    • When exporting from the server character set LATIN (first set of 10 digits, 1112211111), for the session character set UTF8 (the fifth position in the set), the export width is 2.
    • When exporting from the server character set UNICODE (second set of 10 digits, 2222322222) for the session character set UTF8 (the fifth position in the set), the export width 3.
    • When exporting from the server character set KANJISJIS (third set of 10 digits, 1112111111), for the session character set UTF16 (the fourth position in the set), the export width is 2.

Export Width Space Considerations

The export width value is a multiplier, so that if data in the server character set is n bytes, and the export width is 2, the same data in the result set occupies 2n bytes.